I have pretty extensive weapons training, both informal and formal – I can hit targets accurately and consistently at 300 meters. I can disassemble and re-assemble a number of weapons very quickly. I can hit moving targets, and I can even fire fairly accurately dual-wielding pistols action movie style (which is very hard, I might add).
I also don’t panic and I don’t seem to have much of a normal fear reaction.
All that said, if I were to walk into a room where there were one or two bad guys with guns, a bunch of civilians maybe some of whom also had guns, and other confusing and confounding elements, if I had to shoot someone – though I am quite sure I could hit my target accurately, unlike most people – there’s maybe a 50% chance I’d shoot all the right people.
Look at all the advantages up above that I have, and then think about how much worse the average person toting a gun who only fires it at the range would do.
So why the hell would we ever even consider arming teachers and college professors? Really, could you think of any worse idea? Great, not only would half of them lose their guns within a few weeks, but if they ever needed to shoot anyone, most likely they’d shoot everyone.